Frgoboy just prove that using P2P was an easier implementation and low cost, why still arguing on that "why it was designed that way"?
For the ones that said FPS don't need to be "instant" and RTS needs different necessities...what do you really mean? When I shot someone that trying to hide behind a crate, this is VERY important to have real time but, you will NEVER have realtime in multiplayer game...well never say never but actually, it's impossible. I understand Stardock to have chosen P2P and it's ok, but we must all agree that P2P is not a good architecture these days. Back to windows 98 with no firewall, almost no routers and such, it was pretty easy to connect, now it is difficult for almost everyone.
My point is unless you don't play a card game over the internet, you need to have the most quick response from other player, there isn't a lot of different neccessities for MMO, RTS, FPS, Sports etc.
We will need to "accept" that architecture because they won't change it but I guess they will provide support to setup the whole thing. From now on, companies should stop to take P2P as the solution because the networks of today are so complex, just don't blame Stardock...